The density of ethanol, to a great extent, depends on the temperature and pressure of the surroundings. Changes in the temperature and surroundings result in change in the volume of this liquid, which, in turn, results in change in its density.
Ethanol, also referred to as ethyl alcohol or grain alcohol, is a colorless volatile liquid, widely used as a solvent of substances meant for human consumption or contact. Ethanol is derived from grains (such as corn) and grass varieties (such as switch grass). It is basically produced from grains which have a significant sugar content. Its density has a crucial role to play in its myriad uses, which range from being a potent psychoactive drug in various alcoholic beverages, to an alternative fuel in various cars and machines.
Density of Ethanol at Room Temperature
Density is defined as the mass per unit of volume. It basically depends on how closely the atoms are spaced in a particular object or liquid. If the object floats on water, it means the density of the object is less than the density of water, and if the object sinks, it means that its density is more than that of water. The density of a particular object or liquid is measured in g/cm3. In case of ethanol, its average density is 0.789 g/cm3 at the temperature of 20 °C.
| Density of Ethanol at Various Temperatures | |
| Temperature | Density (in g/cm3) |
| 16 °C | 0.79283 |
| 17 °C | 0.79198 |
| 18 °C | 0.79114 |
| 19 °C | 0.79029 |
| 20 °C | 0.78945 |
| 21 °C | 0.78860 |
| 22 °C | 0.78775 |
| 23 °C | 0.78691 |
| 24 °C | 0.78606 |
| 25 °C | 0.78522 |
These figures show that there is an inverse relationship between temperature and density of ethanol. As the temperature decreases, the density increases, and as the temperature increases, it decreases.
Accepted Density
The accepted density of this liquid is 0.789 g/cm3, and its energy density is 26.8 mega-joules per kg. When producing ethanol, one has to keep a tab on its density as well as water content.
How to Find the Density?
The mathematical formula to measure the density is p = m/v, wherein p refers to density, m refers to mass, and v refers to volume. You can also measure the density of ethanol using an alcohol monitoring system. Some of the sophisticated alcohol monitoring systems available today can even measure the water content in ethanol. If ethanol contains significant amount of water, it tends to behave more like water then a biofuel―especially when mixed with gasoline.
Ethanol Uses
Over the last few years, the use of ethanol has increased and a large part of the credit for this goes to the physical and chemical properties of ethanol. Today, ethanol is used to manufacture alcoholic beverages, as a solvent for paint, manufacturing of ethanal and ethanoic acid, a fluid in thermometers, preservative for biological specimens, and―most important of all―as a fuel.
Higher the density, more the heat, and thus, it is important. Ethanol is a polar solvent, while gasoline is a hydrocarbon. The polar solvent abilities of ethanol tend to subdue the hydrocarbon emissions of gasoline. As a result of this, there is a drastic decrease in emissions, which makes it an environment-friendly fuel alternative.